:root {
  --primary: #1a472a;
  --primary-light: #2d5f3f;
  --accent: #d4af37;
  --text: #2c2c2c;
  --text-light: #5a5a5a;
  --bg: #fdfcf8;
  --card-bg: #ffffff;
  --border: #e5e1d8;
  --success: #2d5f3f;
  --error: #c7493a;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Crimson Pro', 'Georgia', serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 18px;
}

h1, h2, h3, h4 {
  font-family: 'Archivo', -apple-system, sans-serif;
  font-weight: 600;
  line-height: 1.3;
  color: var(--primary);
}

h1 { font-size: 2.5rem; margin-bottom: 1rem; }
h2 { font-size: 1.8rem; margin: 2rem 0 1rem; }
h3 { font-size: 1.3rem; margin: 1.5rem 0 0.75rem; }
h4 { font-size: 1.1rem; margin: 1.5rem 0 0.75rem; }

.congrats {
  color:#fdfcf8
}


/* Layout */
.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 3rem 2rem;
}

/* Breadcrumbs */
.breadcrumbs {
  font-family: 'Archivo', sans-serif;
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

.breadcrumbs a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s;
}

.breadcrumbs a:hover {
  color: var(--accent);
}

.breadcrumbs span {
  margin: 0 0.5rem;
}

/* Cards */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  padding: 2rem;
  margin: 2rem 0;
  border-radius: 2px;
}

.card h2 {
  margin-top: 0;
}

.intro-section {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: white;
  padding: 2.5rem;
  border-radius: 2px;
  margin-bottom: 2rem;
}

.intro-section h2 {
  color: white;
  margin-top: 0;
}

.objectives {
  list-style: none;
  margin-top: 1.5rem;
}

.objectives li {
  padding-left: 1.5rem;
  position: relative;
  margin: 0.75rem 0;
}

.objectives li:before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: bold;
}

.list {
  list-style: none;
  margin-top: 1.5rem;
}

.list li {
  padding-left: 1.5rem;
  position: relative;
  margin: 0.75rem 0;
}

.list li:before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: bold;
}

/* Lecture content */
.lecture-section {
  margin: 2.5rem 0;
  padding: 2rem;
  background: var(--card-bg);
  border-left: 4px solid var(--accent);
}

.lecture-section h3 {
  margin-top: 0;
}

.example {
  background: var(--bg);
  padding: 1.25rem;
  margin: 1rem 0;
  border-left: 3px solid var(--primary-light);
  font-style: italic;
  font-size: 0.95rem;
}

/* Navigation buttons */
.nav-buttons {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin: 2rem 0;
  justify-content: space-between;
}

.btn {
  font-family: 'Archivo', sans-serif;
  padding: 0.875rem 1.75rem;
  border: 2px solid var(--primary);
  background: var(--card-bg);
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.2s;
  border-radius: 2px;
  display: inline-block;
}

.btn:hover {
  background: var(--primary);
  color: white;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-light);
  border-color: var(--primary-light);
}

.btn-again {
    margin-top: 18px;
}

/* Activities */
.activity {
  background: var(--card-bg);
  border: 1px solid var(--border);
  padding: 1.75rem;
  margin: 1.5rem 0;
  border-radius: 2px;
}

.activity-prompt {
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 1rem;
}

.activity input,
.activity textarea {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 2px;
  font-family: 'Crimson Pro', serif;
  font-size: 1rem;
  margin: 0.5rem 0;
}

.activity textarea {
  min-height: 100px;
  resize: vertical;
}

.hint {
  font-size: 0.9rem;
  color: var(--text-light);
  font-style: italic;
  margin-top: 0.5rem;
}

.answer-feedback {
  margin-top: 1rem;
  padding: 1rem;
  border-radius: 2px;
  display: none;
}

.answer-feedback.correct {
  background: #e8f5e9;
  color: var(--success);
  border: 1px solid var(--success);
  display: block;
}

.answer-feedback.show {
  display: block;
}

/* Exercise options */
.exercise-options {
  list-style: none;
  margin: 1rem 0;
}

.exercise-options li {
  padding: 0.875rem;
  margin: 0.5rem 0;
  background: var(--bg);
  border: 2px solid var(--border);
  cursor: pointer;
  transition: all 0.2s;
  border-radius: 2px;
}

.exercise-options li:hover {
  border-color: var(--primary);
  background: white;
}

.exercise-options li.selected {
  border-color: var(--primary);
  background: white;
  font-weight: 600;
}

.exercise-options li.correct {
  border-color: var(--success);
  background: #e8f5e9;
}

.exercise-options li.incorrect {
  border-color: var(--error);
  background: #fce4e4;
}

.explanation {
  margin-top: 1rem;
  padding: 1rem;
  background: var(--bg);
  border-left: 3px solid var(--accent);
  font-size: 0.95rem;
  display: none;
}

.explanation.show {
  display: block;
}

/* Quiz */
.quiz-container {
  background: var(--card-bg);
  padding: 2rem;
  border: 1px solid var(--border);
  border-radius: 2px;
}

.quiz-question {
  margin: 2rem 0;
}

.quiz-number {
  font-family: 'Archivo', sans-serif;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.quiz-result {
  text-align: center;
  padding: 2rem;
  margin: 2rem 0;
  display: none;
}

.quiz-result.show {
  display: block;
}

.quiz-result.success {
  background: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 100%);
  color: var(--success);
  border: 2px solid var(--success);
  border-radius: 2px;
}

.quiz-result.success h2 {
  color: var(--success);
}

.quiz-result.retry {
  background: #fff3e0;
  border: 2px solid #f57c00;
  border-radius: 2px;
}

/* Assignment */
.assignment-option {
  background: var(--card-bg);
  border: 2px solid var(--border);
  padding: 1.75rem;
  margin: 1.5rem 0;
  cursor: pointer;
  transition: all 0.2s;
  border-radius: 2px;
}

.assignment-option:hover {
  border-color: var(--primary);
}

.assignment-option.selected {
  border-color: var(--primary);
  background: var(--bg);
}

.assignment-option h3 {
  margin-top: 0;
  color: var(--primary);
}

.peer-review-section {
  background: var(--bg);
  padding: 2rem;
  margin-top: 2rem;
  border-left: 4px solid var(--accent);
}

.criteria-list {
  list-style: none;
}

.criteria-list li {
  padding: 0.5rem 0 0.5rem 1.5rem;
  position: relative;
}

.criteria-list li:before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--success);
  font-weight: bold;
}

/* Confetti animation */
@keyframes confetti-fall {
  to {
    transform: translateY(100vh) rotate(360deg);
  }
}

.confetti {
  position: fixed;
  width: 10px;
  height: 10px;
  background: var(--accent);
  animation: confetti-fall 3s linear forwards;
}

/* Responsive */
@media (max-width: 768px) {
  body {
    font-size: 16px;
  }
  
  .container {
    padding: 2rem 1.25rem;
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  
  .nav-buttons {
    flex-direction: column;
  }
  
  .btn {
    width: 100%;
    text-align: center;
  }
}

/* Google Fonts import */
@import url('https://fonts.googleapis.com/css2?family=Archivo:wght@400;600;700&family=Crimson+Pro:ital,wght@0,400;0,600;1,400&display=swap');
/* Conclusion Page */
#conclusion-page .intro-section {
  text-align: center;
}

#conclusion-page .lecture-section {
  margin-top: 2rem;
}
/* Unit Selector */
.unit-selector {
  width: 100%;
  padding: 0.875rem;
  font-family: 'Crimson Pro', serif;
  font-size: 1rem;
  border: 2px solid var(--border);
  border-radius: 2px;
  background: var(--card-bg);
  color: var(--text);
  cursor: pointer;
  transition: border-color 0.2s;
}

.unit-selector:hover {
  border-color: var(--primary);
}

.unit-selector:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26, 71, 42, 0.1);
}

/* Tabbed Interface for Course Topics */
.tabs-container {
  margin: 2rem 0;
}

.tabs {
  display: flex;
  gap: 0.5rem;
  border-bottom: 2px solid var(--border);
  margin-bottom: 0;
}

.tab-button {
  font-family: 'Archivo', sans-serif;
  padding: 0.75rem 1.5rem;
  background: var(--bg);
  border: 2px solid var(--border);
  border-bottom: none;
  color: var(--text);
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s;
  border-radius: 2px 2px 0 0;
  position: relative;
  bottom: -2px;
}

.tab-button:hover {
  background: var(--card-bg);
  color: var(--primary);
}

.tab-button.active {
  background: var(--card-bg);
  color: var(--primary);
  border-color: var(--border);
  border-bottom: 2px solid var(--card-bg);
}

.tab-contents {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-top: none;
  padding: 2rem;
  border-radius: 0 0 2px 2px;
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

.tab-content h3 {
  margin-top: 0;
  color: var(--primary);
  font-size: 1.3rem;
}

.tab-content .list {
  margin-top: 1.5rem;
}

.tab-content .list li {
  margin: 0.6rem 0;
}

.tab-content .list a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.2s;
}

.tab-content .list a:hover {
  color: var(--primary);
  text-decoration: underline;
}